Process of producing wax-free products from crude petroleum



1 Nw. l 193.55A

E. PETTY "EROCBSS OF RODUCIHG WAX FREE 'PRODUCTS' FROM CRUDE PETROLEUM Filed July 1:1'. 1923 IYITIYZSSJ- l E. PETTY PROCESS 0F PRODUCING WAX'FREE PRODUCTS FROM GRUDE PETROLEUM Fil-ed July 11, 1923 2 snets-sneet IWT/JESS Patented Nov. 3, 19.25.

l 1,559,982 UNITED vSTATES PATENT oFEicE.

EARL PETTY, or WINFIELD, xANsAs, AssIGNoR To THE DE LAVAL sEPARA'roR coin- PANY, or NEW YORK, N. Y., A coRPoRArIoNoF NEW JERSEY:

PROCmS 0F PBODUCING WAX-FREE PRODUCTS FROM CRUDE PETROLEUI. i

'Application ined Juiy 11, 192s. serial No. 650,782.

To all lwho/mA it may ,concer/n.: E Be it known that I, EARL Parri', a citizen of the United States, residing at Winfield, county of Cowley,and State of Kansas, have invented a new and useful Improvement in Processes of Producing Wax-'FreeProducts from Crude Petroleum, of which the 'following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part'of this specification.

In the refining of the crude oils known as paraflin base crude oils, it is customary to distill off successively products of successively higher boiling points, such as naphtha, illuminating oils, gas oils and wax distillates, leaving as a residue stock known as cylinder oil stock. The waxv distillates carry in solution more or less wax (or paraffin) of a crystalline form. The cylinder oil stock contains more or less wax of an amorphous form, having never been broken down by distillation. The 'wax distillates and cylinder oil stock are subjected to` separate and different treatments to purify and decolorize and to separate out the wax content. Examples of such processes are set forth in applications for lpatents filed by me August 24, 1921, Serial No. l495,07 8 and No. 495,079.

The prbcess embodying the present invention has for its object the simplification of known processes to produce the various marketable products heretoforel produced and to obtain more nearly perfect results. The object is attained by a new order and arrangement of sub-processes and more par- 'ticularly by means of a different oi'der and arrangement of the specific steps set forth.

in the patent applications above specified.

The more specific object of my invention is to obtainlwax-ree products of various boiling points and specifically wax-free higher boiling point distillates and Waxfree residual bright stock. 'My process involves treatment of the oil before Aseparating the Wax'and theseparation ofthe wax from the oil Without previously distillin'g off wax distillate and'preferably the separation of thel wax from the crude oil before any substantial distillation, as well as the subsequent treatment ,of the oil so freed from wax. To recover such oil as may be carried o with the wax, my process involves also the treatment of such wax 4for the separation of the oil carried ofi:l therewith and the addition ofsuch oil to a residual product resulting from distillation or to the originally separated'oil. It is therefore necessary to describe hereinzthe treatments to which the crudeoil is sub'ected' Wax before the main separation of oil -an and the treatments to which the wax, as well as such oil, are subjected after their original separation.

An' understanding of the process may be more Vreadily arrived at by describing the same in connection with the accompanying drawings, of which Fig. 1 is a diagram of a workable apparatus in which the first part of my process may be carried out, and Figs. i). and 3 are diagrams of thc treatments to which the originally separated oiland Wax are respectively subjected. f

I first add to the crude oil enou h naphtha to build the oil to a 42 B., t e crude oil supply and the naphtha supply being ninto and through a pack of excelsior .f and thence into a De Laval centrifugal oil separator g, wherein the acid sludge and acid 'wash water are separated from the oil. flhe oil from the separator is pumped continuously to a mechanical agitator h, to which 'is continuously supplied, from a tank c', a stream of soda ash or caustic soda. From the agitator Il, the mixture, together with some wash water from a reservoir 7, is pumped through an wherein a more effected, which emulsion continuously outflows to'- another centrifugal separator Z, wherein the caustic sludge and wash water are separated from the neutralized oil. The

excelsior pac .mode of operation of the excelsior packs specified is set forth in' an application led by me August 24, 1921, Serial No. 495,089.

The thus chemically treated and partially purified oil is continuously pumped into a mechanical mixing tank m, to which is continuously supplied, from a supply n, a small thorough emulsion is Idiagi'ainmatically indicated at a and b in k/ra.

ion

l sse proportion of fullers earth, which is intimately mixed with the oil. From the mixer lmI the oil liows continuously into a lpreliminary purifier o, which 1s l preferably a vacuum lter or a basket centrifuge, where-in the bulk of the fullers earth and discolor'- ing matter carried thereby are removed. The oil is then pumped into a De Laval centrifugal clarifier p wherein the oil is completely freed of the lter media and the remaining discoloring matter.

The thuschemically treated and filtered oil is then reduced to a temperature suicient to throw the wax out of solution, say to a temperature of about 2()o F. This re'- frigeration mayv be effected by running the oil through a double pipe chlller fr in heat exchange-relation with an oppositely iiow-l ing outgoing stream of cold. wax-free oil and thence through a tank or tanks .9 provided with `coils, or shells containing refrigerated brine. The refrigerated mixture then runs into a centrifugal separator t,

where the wax, being the heavier, is thrown to the periphery and the lighter oil dis- `placed inwardly; wax-free oil being discharged from the light liquid outlet and wax carrying comparatively little oil from the heavy liquid outlet. The Wax-free oil is then brought into heat exchange relation with the solution of oil and wax lowingtoward the separator, as above described. y

`Thewax-free crude oil is now subjected to the usual distillation (say in still u) for reduction to naphtha, illuminating oils, and gas oil (see Fig. 2), leaving residue A. The distlllation is then continued for reduction to low pour neutraloils' (spindle, light, medium, heavy,'fred), a low pour residue B remaining in the stil This residue is diluted with naphtha and subjected to the same chemical and decolorizing treatments as those to which the crude oil .was subjected. This treatment will be rap1d. The thuspurified lubricating stock 1s placed in steam stills or vacuum stills and vcarefully distilled for recovery of naphtha and reduction to finished low pour brightl stock (residue C, Fig. 2).

In distilling the wax-free crude oil, as above described, after the illuminating oil has been distilled off, leaving residue A, the- ,distillation may be carried on, as above stated, lto make as man gravity cuts as desire (for example, of spmdle,` light, medium, heavy',` etc.) and earchv of these cuts vmay be blended with naphtha and subjected to a chemicall and liltration treatment, as di ammed in Fig.v 2, essentially the same as't at which was apr plied to the vcrude stock but'operating much more rapidly. Each distillate is then reduced for separation and recovery of the separate different naphtha. The distillation for' drawing olf the 4naphtha is done preferably in vacuum Stillsv at a ve low temperature so that the color will not eiin aired. l The wax carryin comparatively little oil) separate from t e crude oil, as hereinbefore described, is warmed and then treated chemically and filtered by essentially the sameproce'ssas that described for treating the crude oil, as dia ammed in Fig. 3. The wax is then reduce for separation and recovery of the naphtha. The temperature is then raised to distill olf the proportion of crystalline wax desired, leaving Vin the still a residue (D) which is more or less entirely lamorphous wax. The wax distillate resultin from the` above, treatment ucorresponds 1n character with the products known as wax distillates Vproduced by the usual process of fractional distillation of crude oil, except that the wax distillate produced by my process is much,`

heavier in wax.

The wax distillate is treated in accordance with the process set forth in my. application filed ugust 24, 1921, Serial No. 495,079. This process comprises dilutionwith naphtha, treatment with sulfuric acid, washingwith water, treatment. with an alkali, washing with water, removal of heavier impurities by centrifugation, v and separation ofthe wax and oil by refrigeration and centrifugation. The waxfree oil is added to the viscous residue remaining after the distillation of the' wax from the crude oil, either after all the .possible distllates have 'been taken ofil (residue B), as in one described embodiment of my process, or after.

ing treatment, I intend to include the herein specifically described successive treatments with an acid and an alkali and filtration, whereby the oil is largely freed from impurities and more or less decolorized, al-

the specific. treatments described.4

I do-not herein claim. the treatment to' which the wax is subjected, after it is separated from the crude oil, except as a part of a more specific' embodiment of my invention, this Iwax treatment forming a part of the process set forth and claimed injan application filed by me September 15, 1921,

.Serial No. 500,755, which application spe-l though I do not intend to limit myself to 1. The process of treating paratlin baise l crude mineral oil to obtain therefrom Waxfree products of various boiling points, which comprises subjecting the oil, before distillation, to successive treatments with an acid and an alkali, to filtration and to refrigeration, thereby producing a partially purified crude oil containing wax` not in solution, separating the wax from the oil by centrifugal force, and distilling the waxfree oil to obtain therefrom substantially wax-free products of ditl'erent boiling points.

2. The. process of treating paraffin base crude mineral oil to obtain therefrom a Waxfree low pour bright stock, which comprises subject-ing the oil, without distilling ott' Wax distillate, to refrigeration and centrifugal separation to separate wax from the oil,

distilling the Wax-free oil to obtain there-` from distillates of different boiling points, diluting the residue with a low boiling point petroleum distillate, subjecting the thus formed treatments with an acid and an alkali, and distilling ofi' the diluting distillate.

3. rl`he process of treating paraflin base crude mineral oil to obtain therefrom awaxfree louy pour bright stock, which comprises subjecting the oil, IWithout distilling off wax distillate, to successive.treatments With an acid and an alkali, and to refrigeration and centrifugal separation to separate Wax from the oil, distilling thewaX-fiee oil lto obtainv `therefrom distillates of different boiling points, diluting the. residue with a low boiling point petroleum distillate, subjecting the thus formed blended stock to successive treatments with an acid and an alkali, and distilling oli' the'diluting distllate. I

-L The process of treating paraflin base crude mineral oil to obtain therefrom waxfree higher boiling point distillates, which comprises subjecting the oil, Without. distilling' off wax distillate, to refrigeration and centrifugal separation to separate Wax from the oil` distilling the wax-free oil to obtain therefrom distillatesl of various boiling mints, diluting higher boiling point distil ates with a low' boiling point etroleum distillate, .subjecting the dilute' distillates to successive treatments with an acid and an alkali, and distilling off the blended stock to successive diluting distillate to produce substantially' wax-free higher boiling point distillates.

5. The process of treating paraffin' base crude mineral oil to obtain therefrom Waxfree higher boiling point distillate, which comprises subjecting the oil, Without distilling off wax distillates, to successive treatments with an acid and an alkali and to refrigeration and centrifugal separation to separate wax from the oil, distilling the Wax-free .oil to obtain therefrom distillates of various boiling points, diluting higl'ier boiling point distillat-es with a low boiling pointv petroleum distillate, ysubjecting the diluted distillate to successive 'v treatments with an acid and anhalkali, vand distilling off the, diluting distillate to produce -substantially wax-free higher boiling point distillates.

6. The process of treating paraffin base crude mineral oil to obtain therefrom Waxfree higher boiling point distllates and low pour bright stock, which comprises subject-ing .the oil, without distilling ott' wax distillate, to refrigeration and centrifugal separation to separate wax from the oil, distilling the wax-free oil to obtain therefrom lower and higher boiling point distillates, diluting higher boiling point distillates with a lowboiling point petroleum distillate, successive treatments with an acid land an alakli, diluting the residue of said distillation with a low boiling point petroleum distillate, subjecting the diluted residue to successivet-reatments with an acid and au alkali, and subjecting the diluted purified distillate and the diluted purified residue to lseparate distillations to drive off the diluting distillates.

The process of treating paraffin base crude oil to obtain therefrom Wax-free. products, which comprises subject-ing the oil,v Without distilling off Wax dist-illatmto rcfrigeration and centrifugal separation to separate from the oil wax carrying compara-tively little oil, distilling the wax free voil to obtain therefrom distillates yof different boiling points, distilling the wax to drive oil' a crystalline Wax distillate, subjecting the crystalline wax distillate to rcfrigeration, and centrifuging the refriga'ted wax to eliminate. substantially .all the oil carried thereby, thereby recovering, free from Wax,'oil that has not been separated from the wax in the lirst specified centrifugal treatment..

In testimony of whichinvention, I have hereunto set my hand, at Tulsa., on this 22 day of June, 1923.

AvEARL PETTY.

subjecting the diluted-distillate to 

